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Balduf T, Blakemore JD, Caricato M. Computational Insights into the Influence of Ligands on Hydrogen Generation with [Cp*Rh] Hydrides. J Phys Chem A 2023. [PMID: 37436832 DOI: 10.1021/acs.jpca.3c02550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
This work reports a computational investigation of the effect of ancillary ligands on the activity of an Rh catalyst for hydrogen evolution based on the [Cp*Rh] motif (Cp* = η5-pentamethylcyclopentadienyl). Specifically, we investigate why a bipyridyl (bpy) ligand leads to H2 generation but diphenylphosphino-based (dpp) ligands do not. We compare the full ligands to simplified models and systematically vary structural features to ascertain their effect on the reaction energy of each catalytic step. The calculations based on density functional theory show that the main effect on reactivity is the choice of linker atom, followed by its coordination. In particular, P stabilizes the intermediate Rh-hydride species by donating electron density to the Rh, thus inhibiting the reaction toward H2 generation. Conversely, N, a more electron-withdrawing center, favors H2 generation at the price of destabilizing the hydride intermediate, which cannot be isolated experimentally and makes determining the mechanism of this reaction more difficult. We also find that the steric effects of bulky substituents on the main ligand scaffold can lead to large effects on the reactivity, which may be challenging to fine-tune. On the other hand, structural features like the bite angle of the bidentate ligand have a much smaller impact on reactivity. Therefore, we propose that the choice of linker atom is key for the catalytic activity of this species, which can be further fine-tuned by a proper choice of electron-directing groups on the ligand scaffold.
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Affiliation(s)
- Ty Balduf
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Marco Caricato
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
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2
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Ganesan V, Kim JJ, Shin J, Park K, Yoon S. Efficient Nicotinamide Adenine Dinucleotide Regeneration with a Rhodium-Carbene Catalyst and Isolation of a Hydride Intermediate. Inorg Chem 2022; 61:5683-5690. [PMID: 35389623 DOI: 10.1021/acs.inorgchem.2c00059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Regeneration of nicotinamide adenine dinucleotide (NADH) has been the primary interest in the field of enzymatic transformation, especially associating oxidoreductases given the stoichiometric consumption. The synthesized carbene-ligated rhodium complex [(η5-Cp*)Rh(MDI)Cl]+ [Cp* = pentamethylcyclopentadienyl; MDI = 1,1'-methylenebis(3,3'-dimethylimidazolium)] acts as an exceptional catalyst in the reduction of NAD+ to NADH with a turnover frequency of 1730 h-1, which is over twice that of the higher catalytic activity of the commercially available catalyst [Cp*Rh(bpy)Cl]+ (bpy = 2,2'-bipyridine). Offsetting the contentious atmosphere currently taking place over the specific intermediate of the NADH regeneration, this study presents pivotal evidence of a metal hydride intermediate with a bis(carbene) ligand: a stable form of the rhodium hydride intermediate, [(η5-Cp*)Rh(MDI)H]+, was isolated and fully characterized. This enables thorough insight into the possible mechanism and exact intermediate structure in the NAD+ reduction process.
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Affiliation(s)
- Vinothkumar Ganesan
- Department of Chemistry, Chung-Ang University, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Jennifer Juhyun Kim
- Department of Chemistry, Chung-Ang University, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Jeongcheol Shin
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Kiyoung Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Sungho Yoon
- Department of Chemistry, Chung-Ang University, Dongjak-gu, Seoul 06974, Republic of Korea
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3
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Henke WC, Stiel JP, Day VW, Blakemore JD. Evidence for Charge Delocalization in Diazafluorene Ligands Supporting Low-Valent [Cp*Rh] Complexes. Chemistry 2022; 28:e202103970. [PMID: 35006643 PMCID: PMC8857064 DOI: 10.1002/chem.202103970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Indexed: 12/14/2022]
Abstract
Ligands based upon the 4,5-diazafluorene core are an important class of emerging ligands in organometallic chemistry, but the structure and electronic properties of these ligands have received less attention than they deserve. Here, we show that 9,9'-dimethyl-4,5-diazafluorene (Me2 daf) can stabilize low-valent complexes through charge delocalization into its conjugated π-system. Using a new platform of [Cp*Rh] complexes with three accessible formal oxidation states (+III, +II, and +I), we show that the methylation in Me2 daf is protective, blocking Brønsted acid-base chemistry commonly encountered with other daf-based ligands. Electronic absorption spectroscopy and single-crystal X-ray diffraction analysis of a family of eleven new compounds, including the unusual Cp*Rh(Me2 daf), reveal features consistent with charge delocalization driven by π-backbonding into the LUMO of Me2 daf, reminiscent of behavior displayed by the workhorse 2,2'-bipyridyl ligand. Taken together with spectrochemical data demonstrating clean conversion between oxidation states, our findings show that 9,9'-dialkylated daf-type ligands are promising building blocks for applications in reductive chemistry and catalysis.
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Affiliation(s)
- Wade C. Henke
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Jonah P. Stiel
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Victor W. Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D. Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
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Nahaei A, Mandegani Z, Chamyani S, Fereidoonnezhad M, Shahsavari HR, Kuznetsov NY, Nabavizadeh SM. Half-Sandwich Cyclometalated Rh III Complexes Bearing Thiolate Ligands: Biomolecular Interactions and In Vitro and In Vivo Evaluations. Inorg Chem 2022; 61:2039-2056. [PMID: 35023727 DOI: 10.1021/acs.inorgchem.1c03218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A class of cyclometalated RhIII complexes [Cp*Rh(ppy)(SR)] bearing thiolate ligands, Cp* = pentamethylcyclopentadienyl, ppy = 2-phenylpyridinate, and R = pyridyl (Spy, 2), pyrimidyl (SpyN, 3), benzimidazolyl (Sbi, 4), and benzothiazolyl (Sbt, 5), were produced and identified by means of spectroscopic methods. The in vitro cytotoxicity of the RhIII compounds in three different human mortal cancerous cell lines (ovarian, SKOV3; breast, MCF-7; lung, A549) and a normal lung (MRC-5) cell line were evaluated, indicating the selectivity of these cyclometalated RhIII complexes to cancer cells. Complex 5, selected for in vivo experiment, has shown an effective inhibition of tumor growth in SKOV3 xenograft mouse model relative to control (p-values < 0.05 and < 0.01). Importantly, the outcomes of H&E (hematoxylin and eosin) staining and hematological analysis revealed negligible toxicity of 5 compared to cisplatin on a functioning of the main organs of mouse. Molecular docking, UV-vis, and emission spectroscopies (fluorescence, 3D fluorescence, synchronous) techniques were carried out on 1-5 to peruse the mechanism of the anticancer activities of these complexes. The obtained data help to manifest the binding affinity between the rhodium compounds and calf thymus DNA (CT-DNA) through the interaction by DNA minor groove and moderate binding affinity with bovine serum albumin (BSA), particularly with the cavity in the subdomain IIA. It can be concluded that the Rh-thiolate complexes are highly promising leads for the development of novel effective DNA-targeted anticancer drugs.
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Affiliation(s)
- Asma Nahaei
- Professor Rashidi Laboratory of Organometallic Chemistry, Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Zeinab Mandegani
- Professor Rashidi Laboratory of Organometallic Chemistry, Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Samira Chamyani
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Masood Fereidoonnezhad
- Toxicology Research Center; Department of Medicinal Chemistry, Faculty of Pharmacy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz 61357-15794, Iran
| | - Hamid R Shahsavari
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Nikolai Yu Kuznetsov
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov st. 28, 119991 Moscow, Russian Federation
| | - S Masoud Nabavizadeh
- Professor Rashidi Laboratory of Organometallic Chemistry, Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran
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5
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Suhr S, Walter R, Beerhues J, Albold U, Sarkar B. Rhodium Diamidobenzene Complexes: A Tale of Different Substituents on the Diamidobenzene Ligand. Chem Sci 2022; 13:10532-10545. [PMID: 36277629 PMCID: PMC9473529 DOI: 10.1039/d2sc03227a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/15/2022] [Indexed: 11/21/2022] Open
Abstract
Diamidobenzene ligands are a prominent class of redox-active ligands owing to their electron reservoir behaviour, as well as the possibility of tuning the steric and the electronic properties of such ligands through the substituents on the N-atoms of the ligands. In this contribution, we present Rh(iii) complexes with four differently substituted diamidobenzene ligands. By using a combination of crystallography, NMR spectroscopy, electrochemistry, UV-vis-NIR/EPR spectroelectrochemistry, and quantum chemical calculations we show that the substituents on the ligands have a profound influence on the bonding, donor, electrochemical and spectroscopic properties of the Rh complexes. We present, for the first time, design strategies for the isolation of mononuclear Rh(ii) metallates whose redox potentials span across more than 850 mV. These Rh(ii) metallates undergo typical metalloradical reactivity such as activation of O2 and C–Cl bond activations. Additionally, we also show that the substituents on the ligands dictate the one versus two electron nature of the oxidation steps of the Rh complexes. Furthermore, the oxidative reactivity of the metal complexes with a [CH3]+ source leads to the isolation of a unprecedented, homobimetallic, heterovalent complex featuring a novel π-bonded rhodio-o-diiminoquionone. Our results thus reveal several new potentials of the diamidobenzene ligand class in organometallic reactivity and small molecule activation with potential relevance for catalysis. Diamidobenzene ligands are versatile platforms in organometallic Rh-chemistry. They allow the isolation of tunable mononuclear ate-complexes, and the formation of a unprecedented homobimetallic, heterovalent complex.![]()
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Affiliation(s)
- Simon Suhr
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Robert Walter
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Julia Beerhues
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Uta Albold
- Institut für Chemie und Biochemie, Freie Universität Berlin Fabeckstr. 34-36 14195 Berlin Germany
| | - Biprajit Sarkar
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
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Kumar A, Comadoll CG, King DS, Oliver AG, Day VW, Blakemore JD. Incorporation of [Cp*Rh] and [Cp*Ir] Species into Heterobimetallic Complexes via Protonolysis Reactivity and Dioximato Chelation. Inorg Chem 2021; 60:14047-14059. [PMID: 34455788 DOI: 10.1021/acs.inorgchem.1c01362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of multimetallic compounds can enable the placement of two or more metals in close proximity, but efforts in this area are often hindered by reagent incompatibilities and a lack of selectivity. Here, we show that organometallic half-sandwich [Cp*M] (M = Rh, Ir) fragments (where Cp* is η5-pentamethylcyclopentadienyl) can be cleanly installed into metallomacrocyclic structures based on the workhorse diimine-monooxime-monooximato ligand system. Six new heterobimetallic compounds have been prepared to explore this synthetic chemistry, which relies on in situ protonolysis reactivity with precursor Ni(II) or Co(III) monometallic complexes in the presence of suitable [Cp*M] species. Solid-state X-ray diffraction studies confirm installation of the [Cp*M] fragments into the metallomacrocycles via effective chelation of the Rh(III) and Ir(III) centers by the nascent dioximato site. Contrasting with square-planar Ni(II) centers, the Co(III) centers prefer octahedral geometry in the heterobimetallic compounds, promoting bridging ligation of acetate across the two metals. Spectroscopic and electrochemical studies reveal subtle influences of the metals on each other's properties, consistent with the moderate M'···M distances of ca. 3.6-3.7 Å in the modular compounds. Taken together, our results show that heterobimetallic complexes can be assembled with organometallic [Cp*M] fragments on the diimine-dioximato platform.
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Affiliation(s)
- Amit Kumar
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Chelsea G Comadoll
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Daniel S King
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Allen G Oliver
- Department of Chemistry and Biochemistry, University of Notre Dame, 149 Stepan Chemistry, Notre Dame, Indiana 46556, United States
| | - Victor W Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
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7
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Kurtz DA, Dhar D, Elgrishi N, Kandemir B, McWilliams SF, Howland WC, Chen CH, Dempsey JL. Redox-Induced Structural Reorganization Dictates Kinetics of Cobalt(III) Hydride Formation via Proton-Coupled Electron Transfer. J Am Chem Soc 2021; 143:3393-3406. [DOI: 10.1021/jacs.0c11992] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Daniel A. Kurtz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Debanjan Dhar
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Noémie Elgrishi
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, Louisiana 70803, United States
| | - Banu Kandemir
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Sean F. McWilliams
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - William C. Howland
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Chun-Hsing Chen
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Jillian L. Dempsey
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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8
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Hopkins Leseberg JA, Lionetti D, Day VW, Blakemore JD. Electrochemical Kinetic Study of [Cp*Rh] Complexes Supported by Bis(2-pyridyl)methane Ligands. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Julie A. Hopkins Leseberg
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Davide Lionetti
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Victor W. Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D. Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
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9
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Shahsavari HR, Hu J, Chamyani S, Sakamaki Y, Babadi Aghakhanpour R, Salmon C, Fereidoonnezhad M, Mojaddami A, Peyvasteh P, Beyzavi H. Fluorinated Cycloplatinated(II) Complexes Bearing Bisphosphine Ligands as Potent Anticancer Agents. Organometallics 2020; 40:72-82. [PMID: 34334870 DOI: 10.1021/acs.organomet.0c00728] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A family of cationic cycloplatinated(II) complexes [Pt(dfppy)(P^P)]Cl, dfppy = 2-(2,4-difluorophenyl)pyridine, incorporating bisphosphine ligands, P^P = bis(diphenylphosphino)methane (1, dppm), 1,2-bis(diphenylphosphino)ethane (2, dppe) and 1,2-bis(diphenylphosphino)benzene (3, dppbz), was prepared. The complexes were characterized by means of several analytical and spectroscopic methods. These complexes displayed acceptable stability in the biological environments which was confirmed by NMR, HR ESI-MS and UV-vis techniques. The antiproliferative properties of these complexes were evaluated by National Cancer Institute (NCI) at National Institutes of Health (NIH) against 60 different human tumor cell lines such as leukemia, melanoma, lung, colon, brain, ovary, breast, prostate and kidney. These complexes showed higher cytotoxicity than cisplatin against a wide variety of cancer cell lines such as K-562 (leukemia), HOP-92 (lung), HCT-116 (colon), OVCAR-8 (ovarian), PC-3 (prostate), MDA-MB-468 (breast), and melanoma cancer cell lines. Complex 3 as the most potent compound in this study furnished an excellent anti-proliferative activity compared to the cisplatin against Hela, SKOV3, and MCF-7 cancer cell lines. The main mode of the interaction of 1-3 with DNA was also determined using molecular docking studies.
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Affiliation(s)
- Hamid R Shahsavari
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran; Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas, 72701, United States
| | - Jiyun Hu
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas, 72701, United States
| | - Samira Chamyani
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran
| | - Yoshie Sakamaki
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas, 72701, United States
| | - Reza Babadi Aghakhanpour
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran
| | - Christopher Salmon
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas, 72701, United States
| | - Masood Fereidoonnezhad
- Department of Medicinal Chemistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, 61357-15794, Iran
| | - Ayyub Mojaddami
- Department of Medicinal Chemistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, 61357-15794, Iran
| | - Parnian Peyvasteh
- Department of Medicinal Chemistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, 61357-15794, Iran
| | - Hudson Beyzavi
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas, 72701, United States
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10
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Hopkins JA, Lionetti D, Day VW, Blakemore JD. Synthesis and Reactivity Studies of a [Cp*Rh] Complex Supported by a Methylene-Bridged Hybrid Phosphine-Imine Ligand. J Organomet Chem 2020; 921. [PMID: 32773887 DOI: 10.1016/j.jorganchem.2020.121294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
[Cp*Rh] complexes (Cp* = η 5-pentamethylcyclopentadienyl) supported by bidentate chelating ligands are useful in studies of redox chemistry and catalysis, but little information is available for derivatives bearing "hybrid" [P,N] chelates. Here, the preparation, structural characterization, and chemical and electrochemical properties of a [Cp*Rh] complex bearing the κ2-[P,N]-2-[(diphenylphosphino)methyl]pyridine ligand (PN) are reported. Cyclic voltammetry data reveal that [Cp*Rh(PN)Cl]PF6 (1) undergoes a chemically reversible, net two-electron reduction at -1.28 V vs. ferrocenium/ferrocene, resulting in generation of a rhodium(I) complex (3) that is stable on the timescale of the voltammetry. However, 1H and 31P{1H} NMR studies reveal that chemical reduction of 1 generates a mixture of products over a 1 h timescale; this mixture forms as a result of deprotonation of the methylene group of 1 by 3 followed by further reactivity. The analogous complex [Cp*Rh(PQN)Cl]PF6 (2; PQN = κ2-[P,N]-8-(diphenylphosphino)quinoline) does not undergo self-deprotonation or further reactivity upon two-electron reduction, confirming the reactivity of the acidic backbone methylene C-H bonds in the PN complexes. Comparison of the electrochemical properties 1 and 2 also shows that the extended conjugated system of PQN contributes to an additional ligand-centered redox event for 2 that is absent for 1.
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Affiliation(s)
- Julie A Hopkins
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, KS 66045, United States
| | - Davide Lionetti
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, KS 66045, United States
| | - Victor W Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, KS 66045, United States
| | - James D Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, KS 66045, United States
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